* {
    margin: 0;
    padding: 0;
}
body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: linear-gradient(to top, #537895, #09203f);
}

.effect {
    width: 320px;
    height: 320px;
    border-radius: 50%;
    background-color: white;
    // 配合这块
    filter: contrast(10);
    .bigball,
    .smallball {
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        padding: 10px;
        border-radius: 50%;
        // 这个模糊就没有了，很神奇
        filter: blur(5px);
    }
    .bigball {
        width: 100px;
        height: 100px;
        background-color: black;
    }
    .smallball {
        width: 60px;
        height: 60px;
        background-color: red;
        animation: ball 3s infinite;
    }
}

@keyframes ball {
    0%,
    100% {
        left: 50px;
        width: 60px;
        height: 60px;
    }
    4%,
    54% {
        width: 60px;
        height: 60px;
    }
    10%,
    60% {
        width: 50px;
        height: 70px;
    }
    20%,
    70% {
        width: 60px;
        height: 60px;
    }
    34%,
    90% {
        width: 70px;
        height: 50px;
    }
    41% {
        width: 60px;
        height: 60px;
    }
    50% {
        left: 270px;
        width: 60px;
        height: 60px;
    }
}
